update magical ingredients rules

rules/spells.tex

@@ -10,7 +10,7 @@
   \item
   A failed spell rips double the normal \glspl{mp} from the caster.
   \item
-  Spell components can add +1 \gls{mp} to a basic element, and allow the caster to cast as if they had +1 in that elemental sphere.
+  Some spell \glspl{ingredient}, pulled from the heart of a plant, or the guts of an animal, can boost a caster's Sphere level by +1 for a single moment.
   \item
   Spells cannot target something too far below their range.
   \begin{itemize}